Arch joist and floor construction



H. F. FREASE ARCH JOIST AND FLOOR CONSTRUCTION `lune 30, 1931..

Filed Aug. 16, 1926 Patented .une 30, 1931 UNITED `ls "IATEs lHunxfrnnr. F. rnnAsn, or CANTON, OHIO ARCH JOIST AND FLO'R CONSTRUCTION Application 'lec. August 16, v1926. Serial No. 129,424.

The invention relates to structures and structural. members for supporting transverse loads, and more particularly toarch y 'oists and to fir-e resisting arch floors made y the use of arch joists. Y Y i From .the structural standpoint, floors have heretofore been made by the use of joists having solid or trussed webs, the joists supporting on their upper chords metal lath covered by a layer of concrete or the like for the floors, and in some cases there being metal lath bellow the jioists and suspended therefrom and having lower surface Vcoatings of plaster or the like for ceilings.

l@ .Such Webbed joist'construction, whether or not including a ceiling as aforesaid, does not satisfy the requirements of fire resisting or so called fire-proof construction, since the load sustaining web membersof the joists E@ are not provided with protective coatings of concrete or the like, and are accordingly subject to the direct action of heat or flames.

Qn the .other hand, solid reinforced concrete .floors of ordinary construction, while satisfying the requirements of lire-resisting construction, are relatively inconvenient to make and exceedingly difficult to alter or repair. In making reinforced concrete floors, separate forms arerequired to support the floor while being poured .and the forms are afterwards removed; and when it is desired, asis usually the case, to have plumbing, heating and Ventilating pipes, electric power and light conduits, and the like between the floor f5 and ceiling, it is necessary to install such pipes and conduits and support themon Ythe oorforms before the concrete is poured. In the finished floor these pipes and conduits are-solidly embedded in theconcrete; and ac- 4@ cordingly if at any time repairs or changes are required for any of the pipes or conduits, it necessary to resort to substantially quarrying operations to break through the 50 atcertain tonnage per month. Thus, .a unit capital investment of $100,000, maybe re quired to provide machinery and equipment V having a maximum productive capacity of 1,000 tons per month. When the tonnage of sales reaches 1,000 tons per month, it is neces sary either to curtail sales effort, or to make another minimum unit investment of $100,000 to provide an addition productive capacity of 1,000 tonsa 0n the other hand semi-finished structural shapes such as rolled I beams and channels, tooheavy for joist floor construction, are usually available on the open market or on short notice from the mills in very large quantities. There is usually also an eX- cess of ordinary structural fabricating plant capacity near mostv of the large markets for structural materials.

The objects of the present invention generally are to overcome the foregoing structural and economic diliicultiesand to improve joist and floor construction, and specifically are: Firs, yto provide a joist floor constructionsatisfyng the requirements of lire resisting construction, and in which all load carrying members are. protected by adequate coatings of concrete and the like.

Second, to provide an arch joist floor construction having a domed chamber between floor and ceiling clear in all-directions for receiving pipes, conduits and the like, and to which'domed chamber access may be `had at any time to repair or change the pipes, con-` duits, and the like contained therein. Y

Third, to provide a concrete floor construction having self sustaining joist and lath re' inforcing for supporting the concrete while setting, and requiring no separate forms for that purpose. 1

Fourth, to provide a relatively light joist floor construction adapted for carrying rela tively heavy loads, and in which an increase in load requiresa relatively slight increase in joist weight. Y i

Fifth, to provide a joist construction adapted to be made of standard structural shapes fabricated by the Vuse of standard equipment and machinery. I

These and ancillary objects are attained by 4a construction and arrangement which may tie rods for lire resisting purposes.

arch joists, preferably embodying improvements of the arch structure set forth in my prior application for U. S. patent, Serial No. 94,757, filed March 15, 1926, and which improvements include rigid triangular arch struts having apexes and bases opposite the apexes, means connecting adjacent apexes to each other and adapted to be flexed, heel struts depending from the bases of the arch struts, means as a tie rod spaced from the apexes and connecting the heel struts and adapted for flexing the apex connecting means, and end supports extending beyond the bases above the heel strut connecting means.

The improved arch oists are used to make the improved arch floors, and for this purpose a plurality of the joists are laterally spaced from each other and supported by their end supports upon carrying beams. Lower metal lath is suspended from the oists below the tie rods, and concrete or the like is poured upon the lower metal lath to form a ceiling and to a depth sufficient to properly embed the Upper metal lath is then suspended from the joists below the arch struts, and concrete or the like is poured upon the upper metal lath to a depth sufficient to properly embed the arch struts for fire resisting purposes, the upper concrete and the arch struts uniting with each other to form a reinforced concrete floor arch, which with the reinforced ceiling concrete, forms a domed chamber between the floor and ceiling for pipes, conduits and the like.

Preferred embodiments of the improved arch joist and floor construction are illustrated in the accompanying drawings, forming part hereof, in which- Figure 1 is a sectional prospective view of the improved arch iioor construction;

Fig. 2, a side elevation of one of the improved arch joists therefor;

Fig. 3, a plan view ofthe joist;

Fig. it, an enlarged fragmentary transverse cross-section of the oist, as on linefl-Ll, Figs. 2 and 8;

-Fig. 5, a transverse cross-section of the joist, as on line 5, Figs. 2 and 3; and

Fig. 6, elevation views illustrating the method of preparing the triangular T arch struts for a j oist from a length of a standard I beam.

Similar numerals refer to similar parts throughout the drawings.

The improved arch joist, indicated generally at 1, includes tapered rigid triangular T-arch struts 2a and 26, which may be and preferably are cut from a standard rolled I- beam, as illustrated in Fig. 6. In the joist, the T-struts 2a and 26 are arranged with their apexes 3a and 86 preferably abutting each other, as at 4, and the ap xes of the abutting struts are connected with each other as by means of splice plate 5 secured to the apex ends of the flanges 6a and 66 of the T-arch struts, as by rivets 7, and the splice plate being adapted to be flexed to accommodate a varying angle between the arch struts in the vertical plane thereof.

Heel struts 8a and 8a are secured to, as by rivets 7, and depend from the base 9a of the arch strut 2a; and heel struts 86 and 86 are secured to, as by rivets 7, and depend from the base 96 of the arch strut 26.

The heel struts are preferably made by angle cutting the web of a standard channel in a manner similar to that shown for preparing the arch struts from standard I-beams, and by notching the lower ends of the channel legs, as indicated at 10 in Fig. 5.

For providing tie rod sleeves 11a and 116 at the lower ends of the heel struts, U-straps 12a and 126 are secured, respectively as by rivets 7 to the lower apex ends of the heel struts 8a and 8a', and 86 and 86; and each pair of heel struts 8a and 8a and 86 and 86', may be spaced from each other at their lower ends as by a spacer plate 18.

A tie rod lll is provided with threaded ends 14a and 146, which extend through the sleeves 11a and 116 respectively, and nuts 15a and 156 are screwed upon the threaded ends lfla and 146 of the tie rod for abutting the U- straps and the lower notched ends of the heel struts, as illustrated.

For resisting lateral displacement of the strut apexes and 36, a pair of guide angles 1G and 16 may be secured as by rivets 7 to the apex 36 of the T-strut Q6, thus forming a U-notch guide for the apex 3a of thestrut 2a.

For providing end supports for the arch joist above the tie rod, spaced angle end supports 17a and 17a', and 176 and 176 are secured as by rivets 7 to the upper outer corners of the struts 2a and 26, respectively, at the bases 9a and 96 thereof.

The end supports 17 a and 17 a, and 17 6 and 176, are preferably made as best illustrated in Fig. 3, by centrally notching one leg of an angle, and bending the angle about the other leg to integrally connect the outer end of the end support 17a and 17a as by the integral leg spacer 18a and to integrally connect the end support 176 and 17 6 as by the integral leg spaced 186. p

The angle end supports may extend beyond the ends of the arch struts any desired distance to provide adequate shear and bearing support for the joist.

In use the tie rod nuts a and 156 may be screwed up upon the tie rod 14 and against the sleeves and the lower ends of the heel struts, to provide any desired arch for the 1 arch struts by HeXing the apex connection 5 for the struts, and to tighten and secure the structure. Any desired adjustment of the tie rod nut may be locked as by hammering over the thrdeads in the ends 14a and 146 of the tie ro s.

The arch joist 1, as aforesaid, embodies the arch structure set forth in my prior application for U. S. Patent Serial No. 94,757, filed March 15, 1926, and improvements therein.

These improvements include the provision of the depending heel struts for the bases of the arch struts, whereby any desired distance may be secured between the upper, preferably horizontal, flanges of the arch struts, and the lower tie rod spaced below the arch struts.

By these means very Vdeep and very strong arch joists may be made requiring relatively small increases in material for relatively great increases in strength; since the greater the depth of the joist, that is to say, the greater the distance between the struts and the tie rod, the greater its strength, and the depth of the joist may be increased by merely lengthening the depending heel struts.

Joists having solid or trussed-A webs, require a much greater increase in weight of web members for increasing their depth and strength than do arch joists of the present construction.

A further improvement of the present construction over the disclosure of my prior application aforesaid, is the utilization of standard I-beams and channels for making the various component parts of the present improved arch joists.

The above described improved Earch joists may be used to make the improved lire resisting arched floor having a ldome chamber between ioor and ceiling clear in all directions for receiving pipe conduits and the like; and to which dome chamber access may be had at any time to repair or change the pipes, conduits, and the like contained therein; and the fire resisting protective coating and re- 'inforcing material, such as concrete, for

which floor may be poured without the use of any separate forms.

The improved arch floor indicated generally at 20, is made by pendulously supporting upon their end supports, a plurality of lateraliy spaced improved arch oists 1 on suitable bearings, such as the beams 21a and 2lb of a building.

Lower metal lath 22 is then suspended as by means of wires 23 from and below the tie rods 14 of the joists, and Ceiling concrete or the like 24, is poured upon the lower metal la' h from above to form a ceiling, and to a depth sufficient to properly embed the tie rods for fire resisting purposes.

Upper metal lath 22 is then suspended from and below the arch struts of the joist-s, as by means of wires 23, and floor concrete or the like 24 is poured upon the upper metal lath to a depth suflicient to properly embed the arch struts for lire resisting purposes; and the upper concrete and the arch struts unite with each other to form the reinforced concrete floor arch 25, whichwiththe reinforced ceiling Aconcrete forms a dome chamber 26, between the-floor andv ceiling, "clear inall directions for receiving ,and `supporting pipes 27..,conduits 28 `andthe like. i

For providing access to the dome chamber 26 for Iinserting the pipes and conduits after the improved arch floor has been made, and for repairing'or changing the pipes, conduits, and the like contained therein at any time, removable bridging slabs 29 may be supported upon suitable ledges 30 formed at the ends of spaced and adjacent lengths of the improved arch floor.

lhile' it isv preferred to utilize the vimproved arch joists as aforesaid for sustaining lower and upper metal lath, thereby prov-iding self-,sustaining forms and reinforcing for an arch lire resisting floor, as aforesaid; if

Afor any reason a solid reinforced concrete floor is desired, `lower metal lath only maybe supported below the .tie rods, and concrete may be poured thereon to embed not onlythe tie rods but also the arch struts in a solid layer of concrete from ceiling to floor.

The under surface of the lower metal lath .in the-improved arch floor construction,` as illustrated, or in the modified solid floor construction Y just ldescribed may be provided, when desired, with a lower coating 31 of ceiling plaster. V

I claim 1. A structural member including an arch having outer bases, tension means connecting the outer bases of the arch and adapted to resist the end thrust thereof, end supports for the arch, the arch having a T-cros's-section increasing in depth from the center of the arch to each base and the head of the T being above the stem and lying substantially in a Hat plane.

2. A structural member including an arch having outer bases, tension means connecting the outer bases of the arch and adapted to resist the end thrust thereof, end supports for the arch, the arch having a T-cross-section, and the T-cross-section increasing in area from the center of the arch span to the bases.

3. A floor construction including a plurality of arch joists, each arch joist including an arch having outer bases, means for resisting the end thrust of the outer bases, and vertically reacting end supports on the arch extending outwardly longitudinally therefrom and transversely spaced from the thrust resisting means, upper material supported by the arches, and lower material supported by the thrust resisting means, and there being formed between the upper and lower material an unobstructd chamber extending across the greater portion of th floor span.

4. A floor construction including a plurality of arch joists, each arch joist including an arch having outer bases, means for resisting the end thrust of the outer bases, and end supports on the arch extending outwardly longitudinally therefrom and transversely spaced from the thrust resisting means, upper material supported by the arches, and lower material supported by the thrust resisting means, and there being formed between the upper and lower material an unobstructed chamber extending across the greater portion of the floor span.

5. A structural member including an arch including web members having outer bases, lever heel struts secured to the outer bases of the web members and depending downwardly therefrom, tension means connecting the lever heel struts and providing lever resista-nce to the end thrust of the arch bases, and end sup* ports for the arch secured to the outer bases of the web members and extending outwardly longitudinally therefrom and transversely spaced from the tension connecting means.

6. A structural member including an arch including web members having outer bases and inner adjacent apeXes, means providing apex abutments between the adjacent apexes and adapted to be flexed, lever heel struts secured to the outer bases of the web members and depending downwardly therefrom, tension means connecting the lever heel struts and providing lever resistance to the end thrust of the arch bases, and end supports for the arch secured to the outer bases of the web members and extending outwardly longitudinally therefrom and transversely spaced from the tension connecting means.

In testimony that I claim the above, I have hereunto subscribed my name.

HURXTHAL F. FREASE. 

